1. Stoichiometric Ratio The stoichiometric ratio between two reactants will be determined experimentally.

2. Principles Stoichiometry is the branch of chemistry that deals with the ratio between reactants and products in a chemical reaction. The net result can be described by a balanced chemical reaction.

3. Principles This balanced equation gives us valuable information about the reaction.

4. Principles 1Mg to 2 HCl 3 Reactants to 2 Products 1 Mg to 1 MgCl 2 2 HCl to 1 MgCl 2

5. Principles In this Lab we will use the heat given off by a reaction to determine its stoichiometry.

6. Principles The amount of heat given off, or Q, can be graphed versus the number of moles of reagent. From the graph the stoichiometry can be determined

10. Calculations Number of moles of reactant: Moles = M V Moles = (0.5mol/L)(0.010L) Change in Temperature:  T = T f – T i  T = 32 o C – 23 o C

11. Procedure Measure appropriate amounts of NaOCl and Na 2 SO 3 Determine the temperatures of both reagents. Do Not use the same thermometer for both reagents

12. Procedure Pour the NaOCl into a clean styrofoam cup. Add the Na 2 SO 3 and record the maximum temperature that the mixture reached. Ensure that the reagents are well mixed

13. Safety It is important that you always keep your safety goggles on.